(1) Technical Field
The present invention relates to a diamond trowel blade. More particularly, this invention relates to a concrete surface preparing trowel blade with diamond particles and a method of using a diamond trowel blade to prepare a concrete surface.
(2) Background
Concrete is one of the most widely used construction materials. Because of its strength, durability, ease of manufacture, ease of installation, and relatively low cost, it is frequently the material of choice for floors, walls, and the like. However, there are many instances where it is desirable to have a floor or wall surface with a pleasing high gloss finish or shine. In such cases, concrete may be overlooked in favor of other more high cost materials such as marble, stone, terrazzo, etc. Color concrete flooring has become very popular replacing the flooring materials previously mentioned as well as low cost tile flooring applications.
In pouring wet concrete, several steps are required to insure a smooth concrete surface finish after the concrete has partially dried. When the concrete is still in semi-fluid form, it is initially screeded through the use of a screed board or long wooden plank. Screeding is required to bring the wet concrete surface to a roughly equal height. Once the concrete is initially set at this height, the surface of the concrete is then treated with a float. The floating operation is used to settle large stones, smooth out the surface of the wet concrete, and settle the larger stones below the surface. After the float operation is performed and the concrete has partially dried, the freshly poured concrete may be troweled in order to bring the surface to a smooth finish. Utilizing a trowel machine with a plurality of blades, the surface of the concrete which is in a partially dried condition is contacted by the rotating blades of the trowel machine and produces a smooth finish surface on the concrete which is free of bubbles and also allows for evaporation of water which may rise to the surface. However, troweling needs to be completed prior to the concrete becoming too hard. Once the freshly poured concrete has hardened, the troweling machine and its corresponding flat blades will not sufficiently smooth the concrete surface.
Color concrete floors have some drawbacks when preparing the surface that include: 1) trowel machines may burn or take the color out of the color concrete floor if used too long while trying to take out imperfections; and 2) color concrete floors must be left in an imperfect or rough finish to harden to avoid burning the floor or taking the color out of the color concrete flooring. There is a need for a device and a method for preparing the concrete surface after the concrete has hardened.
In the past power trowel machines with trowel blades as well as grinding machines with grinding blades have been attempted in numerous ways. U.S. Pat. No. 3,936,212 titled “Ride-Type Surface-Working Machines” and U.S. Pat. No. 5,480,258 titled “Variable Width, Twin Engine Riding Trowel” depict an example of a riding troweling machine for finishing large areas of concrete flooring utilizing traditional trowel blades. U.S. Pat. No. 5,480,258 also depicts a power trowel machine that is expanded to receive finishing pans on the blades of the rotors. U.S. Pat. No. 3,934,377 titled “Concrete Surface Grinder”; U.S. Pat. No. 5,605,493 titled “Stone Polishing Apparatus and Method”; and U.S. Pat. No. 6,238,277 titled “Multidisc Floor Grinder” are examples of rotary concrete surface grinding and smoothing devices having engine driven, and a rotating grinding head. Using these machines requires the additional expense of having both a grinder and a trowel machine for finishing concrete surfaces. U.S. Pat. No. 5,567,503 titled “Polishing Pad with Abrasive Particles in a Non-Porous Binder” discloses a polishing pad of ultra-hard abrasive particles such as diamond or cubic boron nitride for use with non-porous thermoplastic polymers in polishing very had stones such as granite. These pads are designed for very hard stone and do not work as well for concrete surfaces with numerous imperfections. U.S. Pat. No. 6,058,922 titled “Grinding Blade for Trowel Machine” converts the trowel machine to a grinding machine by sliding a device with a grinding stone attached to the device over each trowel blade.
There have also been various methods attempted to finish concrete floors. U.S. Pat. No. 6,155,907 reissued as RE38,364 E titled “Method for Hardening and Polishing Concrete Floors, Walls, and the Like” discloses a method of hardening and polishing a concrete surface by applying a hardening/densifying silicate compound, allowing the chemical to soak into the surface of the concrete, drying the surface, applying a polishing compound and mechanically polishing the concrete surface. This patent also discloses other methods that all include a step of applying silicate polishing compounds or applying a hardening/densifying silicate compounds or both. U.S. Pat. No. 6,475,067 titled “Dry Method of Concrete Floor Restoration” discloses a method for restoring a concrete surface by dry grinding a concrete surface using a grinding grit, extracting the dust generated, repeating the dry grinding and applying a sealer. This process uses rotating diamond grinding disks that remove existing floor coatings or smooth out ruts or pitted concrete floor slabs attached to grinding machines such as the HTC-800 available from HTC Sweden. However, this method uses additional grinding machines and applies sealer coats after grinding.
In order to take advantage of color concrete flooring and avoid the drawbacks there is a need for a device that: 1) can attach to a walk behind trowel machine or a ride able trowel machine; 2) can prepare surfaces of hardened concrete; 3) is inexpensive; and 4) incorporates natural or synthetic diamond abrasive particles.